Double blind crossover, 64 adults, two sessions a week apart

Neuroscience research poster example

A crossover poster lives or dies on whether the reader can see that the same people did both conditions. This board says so in the methods block, gives the centre of the canvas to reaction time across eight blocks of 50 trials, and puts the 31 millisecond difference and its interval where the eye lands next.

Create a poster with OneCraftA0 Landscape, printed at 1189 by 841 millimetres

The whole board

The poster at full size, exactly as it prints. Every number, citation and caption on it was written for this example, so the layout is being judged on real content.

LU
Caffeine and choice reaction time: a within participant crossover across 400 trials a session
M. Devereux ¹, A. Sciortino ¹, K. Obuya ²
1 Cognitive Neuroscience Laboratory, Lowfield University · 2 School of Psychology, Lowfield University
Choice reaction time
Caffeine
Placebo
1
2
3
4
5
6
7
8
0150300450600
Figure 1. Median reaction time in each block of 50 trials, caffeine against placebo. Both conditions slow across the session; the gap does not close.
Source: 63 participants, 50,400 trials, 2026.
Primary outcome
Mean median reaction time was 428.5 ms on caffeine and 459.5 ms on placebo, a within participant difference of 31.0 ms, 95% CI 18 to 44. The advantage is present in the first block and every block after it, from 17 ms in block 1 to 33 ms in block 8, so it is not a late session rescue of a tiring participant. Both conditions slow across the hour, by 34 ms on caffeine and 50 ms on placebo, which means caffeine flattened the drift rather than removing it. Accuracy by condition was 24,242 correct of 25,200 trials on caffeine, 96.2%, and 24,192 of 25,200 on placebo, 96.0%, a difference of 0.2 points, so nothing here looks like speed bought with errors. Forty nine of the 63 participants were faster on caffeine, and the 14 who were not were slower by 11 ms on average.
COMPLETION BY ARM
Caffeine first, session 1
32 of 32
Caffeine first, session 2
31 of 32
Placebo first, session 1
32 of 32
Placebo first, session 2
32 of 32
Abstract
Caffeine is reported to speed simple responses, but the choice task that daily work resembles is tested less often and over fewer trials. Sixty four adults completed a four choice task twice, a week apart, once after 200 mg of caffeine and once after a matched placebo, in randomised order. Responses were 31 ms faster on caffeine, 95% CI 18 to 44, with accuracy unchanged at about 96% in both conditions.
Introduction
Most laboratory evidence on caffeine and speed comes from simple reaction tasks, where a single stimulus needs a single response. Work that matters tends to involve a choice between several responses, where the cost sits in selection rather than detection, and a stimulant that helps one need not help the other. A crossover design answers the question inside each person, which removes the large between person spread in baseline speed that swamps a parallel groups trial of this size, and 400 trials a session gives enough blocks to see whether any gain survives the hour.
METHODS
Design. Within participant crossover, two sessions a week apart, order randomised 1:1, double blind, matched capsules prepared by a third party.
Participants. 64 adults aged 18 to 39, habitual intake under 100 mg a day, no caffeine for 12 hours before each session. 63 completed both sessions.
Dose. 200 mg caffeine or matched placebo, taken 45 minutes before testing, the same clock time in both sessions for each participant.
Task. Four choice reaction task, 400 trials a session split into 8 blocks of 50, with a 60 second rest between blocks. 50,400 trials analysed.
Analysis. Mixed model on median block reaction time with participant as a random effect, condition and block as fixed effects, alpha 0.05.
31 ms
faster on caffeine
95% CI 18 to 44, 63 participants, 50,400 trials
Discussion
Thirty one milliseconds is about 7% of the placebo response and close to the gap between a rested and a mildly tired reading in this task. It is worth having and it is not transformative. The flatter drift is the more useful finding for shift work, because it is the end of the hour, not the start, where the two conditions diverge most.
Conclusions
A single 200 mg dose made choice responses 31 ms faster across a full hour of testing without costing accuracy, and its clearest effect was on how much participants slowed rather than on how fast they started.
Habitual users above 100 mg a day were excluded
One dose only, so nothing here speaks to tolerance
Ages 18 to 39, so no reading for older adults
Laboratory task, not a driving or workplace measure
REFERENCES
1.Brandt, L. and Ferreira, J. (2024) Choice against simple reaction under stimulants: a within participant comparison. Journal of Applied Cognition, 21(2), 145 to 162.
2.Aldridge, S. (2025) Time on task drift and what a crossover can separate from it. Experimental Psychology Methods, 12(1), 33 to 49.
3.Obuya, K., Devereux, M. and Sciortino, A. (2023) Trial counts and the stability of a median block estimate. Lowfield Cognitive Reports, 8(4), 201 to 217.

Block by block

What each block on the board is for, in the order a reader walks it.

Title band and three authors
The title states the design and the trial count rather than the result, so a reader who disagrees with the finding still knows what was done. Three authors sit over two affiliations with the presenting author marked.
Abstract and introduction
The abstract gives the design, the dose and the 31 ms result in four sentences. The introduction explains why a choice task was used instead of a simple reaction task, and why a crossover removes the between person spread that swamps a parallel trial of this size.
Methods as a labelled protocol
Five entries: the double blind crossover with randomised order, the 64 adults and their caffeine restriction, the 200 mg dose timed 45 minutes before testing, the 400 trials in eight blocks, and the mixed model used on median block time.
Centre stage figure
Median reaction time in each block of 50 trials, caffeine against placebo. Eight short numeric tick labels and two short series names keep the axis readable where the legend sits under it.
Primary outcome
The two means, the difference with its interval, the block by block gap from 17 ms to 33 ms, the drift of 34 ms against 50 ms across the hour, and the accuracy counts for both conditions.
Completion by arm
A bar block showing both order arms across both sessions: 32 of 32, 31 of 32, 32 of 32 and 32 of 32. One participant withdrew before the second session, which is why the analysis rests on 63.
Headline number and discussion
The stat block gives 31 ms with its interval and denominators. The discussion sizes it at about 7% of the placebo response and points at the flatter drift as the more useful finding for shift work.
Conclusions, four caveats and references
A short conclusions block, a four item checked list of limits covering habitual users, the single dose, the age range and the laboratory setting, and three numbered references.

What makes this board work

The figure shows every block, not a mean

Eight blocks of 50 trials are plotted for both conditions, so a reader can see that the caffeine advantage is present from block 1 and widens from 17 ms to 33 ms. A single pair of bars would have hidden the more interesting finding, which is the flatter drift.

Accuracy is reported beside speed

A speed result with no error rate invites the obvious question. The board gives 24,242 correct of 25,200 trials against 24,192 of 25,200, a gap of 0.2 points, which closes the speed accuracy tradeoff argument in one line.

The interval travels with the number

The stat block carries 31 ms, the label, and then the interval, the participant count and the trial count underneath. A poster number without its denominator is the defect this block exists to prevent.

Questions people ask

What goes on a neuroscience research poster?

The task, the design, the number of participants and trials, the analysis model, and the effect with its interval. For a within participant study the poster also has to make the crossover visible, because a reader who assumes two separate groups will misjudge both the power and the size of the effect you are reporting.

How do I show a reaction time result honestly?

Plot the blocks rather than a single mean, report accuracy beside speed, and put the interval next to the effect. This board does all three: eight blocks for both conditions, error counts from 25,200 trials in each condition, and a 31 ms difference carrying its 95% interval of 18 to 44.

Should a crossover poster show a flow diagram?

It helps, and this design carries a bar block instead. Completion is shown for both order arms across both sessions, 32, 31, 32 and 32, which is enough to explain why 64 people were enrolled and 63 analysed. Ten of the forty poster designs carry a participant flow block if you want one.

How many trials should a poster report?

Report the number per participant per condition and the total, because the two say different things. This study ran 400 trials a session and analysed 50,400, and the board gives both. A poster that quotes only a total invites a reader to assume far fewer trials per person than there were.

Can I change the chart type on a poster figure?

The design sets it. Ten chart kinds exist across the poster figures, from vertical and horizontal bars to line, area, pie, donut, radar, waterfall and waffle, but each figure block declares its own kind, so the practical move is to pick the design whose figure already matches the shape of your data.

What does an A0 landscape poster export at?

The working canvas is 2,340 by 1,656 pixels and the export captures at twice that, giving 4,680 by 3,312 pixels, about 100 dots per inch at full A0 size. Exports are RGB with no bleed, no crop marks and no CMYK conversion, so a commercial printer will add those if the venue asks for them.

Build your own in about a minute

The button below opens the generator with this use case already described. Change the wording to match your own, generate, then edit anything you like.

Make one like this

Other poster examples

Genetics research poster example

A genetics poster that reports one variant has to answer two questions before anything else: how many samples, and from where. This board puts both in the title band, then gives the whole width to a hero figure showing the variant frequency rising from 0.08 to 0.21 across five regional cohorts of 1,280 samples each.

Agriculture research poster example

A variety trial poster is read table first, because a grower wants the ranking and the agronomist wants the spread. This A0 landscape board puts an eight row results table across the middle, with yield, protein and lodging for each variety, and keeps the method and the caveats on either side of it.

Nutrition research poster example

A dietetics audit poster is read for two things: what the method could actually measure, and which component of the diet is missing. This A0 landscape board photographs 2,400 school lunches across 20 schools, scores each against a guideline, and reports vegetables as the component that fails everywhere.

Want the steps in the builder? Read Add charts and diagrams, then choose the template, theme and size. For everything this generator can do, see the poster maker.

Sources

Written and checked by the OneCraft team. Last checked .